/**
 * @param {string} num1
 * @param {string} num2
 * @param {number} min_sum
 * @param {number} max_sum
 * @return {number}
 */
var count = function (num1, num2, min_sum, max_sum) {
  let MOD = 10e9+7
  let res = 0
  for(let i=num1;i<=num2;i++){
    let sum = i.split('').reduce((pre,cur)=>pre+(cur-0),0)
    if(sum>=min_sum&&sum<=max_sum){
      res++
    }
  }
  return res%MOD
};

count()